1. Field of the Invention
The present invention relates to an image reader for reading document images.
2. Description of the Related Art
FIG. 5 illustrates a portion of a conventional image reading apparatus which includes a document conveying unit 192 for conveying documents. The conveying unit 192 is usually positioned above a reader unit 191 having a document stand 901 for placing a document thereon. A document conveyed by the conveying unit is discharged onto a discharge tray 201 which is attached to the reader unit 191.
Some example of conventional copying apparatuses which utilize document conveying units that convey a document on a document tray to a document stand and then discharges it onto the document tray include Japanese Patent Laid-Open Nos. H03-107176, H01-053963 and H03-138249.
In order to increase the number of documents to be placed on the discharge tray 201, the height of a trailing end wall 202 for restricting the trailing end position of the document placed on the discharge tray 201 may be upwardly increased. That is, as shown in FIG. 5, by elongating the trailing end wall 202 close to a document outlet 921 of the document conveying unit 192, the number of placeable documents may be increased. When a document 906 placed on a document stand 901 is such large-sized that the document 901 exceeds the trailing end wall 202, the following problems arise. When the document conveying unit 192 is closed so as to come close to a document reader 191 after a large-sized document 906 is placed on the document stand 901, the large-sized document 906 is pinched between the document conveying unit 192 and the trailing end wall 202, resulting in the document 906 being bent and/or damaged.
With the apparatus in Japanese Patent Laid-Open No. H03-138249 (see P4, FIG. 3 ), for instance, since when a document is conveyed onto the document stand, a conveying belt is rotated in a direction opposite to that when being discharged onto the document tray from the document stand, the productivity is decreased. Also, when a document is conveyed from the document tray, a document is discharged onto the document tray, so that the document matching is deteriorated, causing the document to frequently malfunction in conveying.
Therefore, in light of the aforementioned deficiencies in the existing conventional image reading systems, it would be desirable to provide an image reading apparatus configured such that it prevent a document from being bent and damaged.